Arduino Pulse Oximeter By Takuya Seaver What is

Arduino Pulse Oximeter By: Takuya Seaver

What is a pulse oximeter? A device that measures the proportion of oxygenated blood through blood vessels. Something that you usually find in a doctors office.

Arduino • In this project I will be using an Arduino to represent the electrical aspect of this project into numbers that can be used as data for the user to see.

Interest • I’ve always had a passion for fitness. Many people want to be fit, but what’s the most optimal way of achieving a person’s goal?

Interest Continued • Some people who talk about the gym have aesthetic goals in mind. One of these goals is to lose fat. What’s the best way to lose fat?

Research • The research shows that a heart rate of around 60%70% is optimal to burn fat. What if a device could tell you exactly when you’ve reached the beginning of the “fat burning zone” and when you’re reaching the limit of the “fat burning zone” so you don’t need to overwork yourself?

Variety of exercise options • This device should not limit the user in any way. Take any form of activity and it will just track your heart rate and let you know when you are in or out of the fat burning zone.

Very Light – best for recovery Light – Basic endurance and fat burning What if fatloss isn’t my main goal? Moderate – improves aerobic fitness Hard – increases performance for shorter durations Maximum – helps athletes for speed

A device in the making • So far, the board is being made. The project is broken up into four main parts: • IR LED and Photodiode • Transimpedance Amplifier • High Pass Filter • AC Gain Stage

• The part I will be using for the IR LED/Photodiode will be CNY 70 which is a reflective optical sensor with transistor output. IR LED and Photodiode

Transimpedance Amplifier • In this project, the transimpedance amplifier will convert a current to a voltage. The photodiode will give off a current which will then be translated to voltage through a resistor, using Ohm’s Law. The output of the op-amp will then be that voltage.

High Pass Filter • A high pass filter removes low frequency signals. It allows for high frequency signals to pass, hence the name. A high pass filter will filter out the signals that are produced from the absorbance of light while allowing the signals from the users pulse to go through.

AC Gain Stage • The AC Gain Stage will use a non-inverting op-amp to amplify the input voltage. The Arduino will then read the output using an analog-todigital converter.

Arduino Lilypad • I plan on using an Arduino Lilypad for my Arduino device. The Arduino Lilypad allows flexibility when testing needs to be done. The Arduino Lilypad can be sewn into clothing which is convenient for my project.

Current Obstacle • The biggest problem so far has been figuring out how to implement the reflective optical sensor into my circuit. Finding out how the pin layout works into my schematic has been somewhat problematic.

Future Obstacle • When it comes time to test the device. There will be the issue of holding the reflective optical sensor in place where there won’t be much disruption.

IR LED/Photodiode Issues • The issue with the IR LED and Photodiode is that they are sensitive to light which can be an issue when the data you want needs to be accurate. The encasement needs to be dark and stable for use, especially when in use for cardiovascular exercise.

Future Plans • I plan on finishing the hardware aspect of the circuit in the near future while I also want to create the basic software aspect of this project after that.

Possible Continuation of the Project • If time allows it, I would like to make an app that can allow the user to track their progress. It would basically be a version of the Arduino program but viewable through your phone.

Questions?